Make ice or buy it?

[LarryFine]

What do restaurants do?

Pass on the costs to the customers.

 

[nakulak]

If you don't want to buy a full size ice maker, buy one of those under the counter bar ice makers that are made for residential. My uncle had one, I think it made around 5 to 10 lbs of ice, maybe more, and was much handier than a stinkin fridge for when people visited. Normal fridges don't make enough ice (IMO). this one is $850, makes 7 gallon of ice http://www.air-conditioner-home.com//vinotemp-vt-imsw/?utm_source=shopzilla&utm_medium=comparisonshopping

 

[BJ Conner]

Manitowoc Ice MAchines

Manitowoc Ice MAchines

Here's a link to Manitowoc Ice machines. Down at the bottom of the page is an Excel sheet for energy calculation for their ice machine.

http://www.manitowocice.com/?xhtml=xhtml/eno/us/en/minisite/energy/savings.html&xsl=minisite.xsl

 

[iwire]

Pass on the costs to the customers.

Yeah that is helpful Larry.:roll:

 

[rattus]

For small amounts of ice, the consensus is that you can't afford any capital outlay. I would make ice at home. Aluminum loaf pans make good molds for the home freezer.

The key thing here is your billable time. Are you making wages when you stop to buy ice? Of course if you stop for a Moon pie and RC Cola, you are there already.

 

[hockeyoligist2]

My supply house has an ice machine, free ice!

 

[mtfallsmikey]

Check restaurant supply houses and auctions, Hoshizaki, Scotsman make small machines....good, low-calcium water supply needed, ice machines can be lots of $$ to maintain.

 

[LarryFine]

Yeah that is helpful Larry.:roll:

Sorry. I misunderstood the question.

 

[gar]

100809-2023 EST

chris:

I have started an experiment with one of my freezers. Ambient is about 85 deg F, and I have performed a calibration of the freezer box. From the start of a warming phase to the start of another warming phase (in other words the ends of cooling phases) was 4.5 hours, and the consumption was 0.78 KWH. Thus, the average KWH per hour was 0.173 or average power was 173 W and assumed to be constant.

I added 1 quart of 70 deg F water at the end of the above test. Thus, at the start of a warming phase. This is about 2.1 #.

If it does not take too long I will get a rough estimate tonight, but the curve is not going down very fast. For you to run the experiment in your freezer I now suggest 1 pint to 1 quart. I put the water on a flat cooking pan with raised edges. Water is about 1/4 to 3/8 deep.

I am going to guess towards 1/4 to 1/2 KWH to cool the water to my average of about - 4 deg F..

Theoretically it should take about (70-32)*2.1 = 80 BTU, plus 144*2.1 = 302 BTU, and plus (32 + 4) * 0.503 * 2.1 = 38 BTU for a total of 80 +302 + 38 = 420 BTU. There are 3413 BTU/KWH. Thus to cool this water should take 420/3413 = 0.123 KWH. But the system is inefficient.

At the present I have been cooling for 1.5 hours. There was an inflection in the temperature curve indicating the the water is frozen and thus we are now below 32 deg F for the water. The compressor has been running continuously. This freezer has cooling coils on the under side of each aluminum shelf. There is no circulating fan.

At this point I have 0.46 KWH for 1.5 hours. Thus, so far the excess required has been 0.46 - 0.26 or 0.2 KWH.

See if there are any errors in my calculations.

.

 

[gar]

100809-2134 EST

The water has cooled sufficiently that the compressor turned off. The current reading is 0.6 KWH and 2.18 hours. So base losses are 0.173 * 2.18 = 0.337 KWH and the difference 0.600 - 0.337 = 0.263 KWH. I will try to get one more heat cool cycle.

On this basis my cost to freeze 1 quart of water would be about $0.035 and 10 # about $0.17 .

Also note this data provides a means to approximate the efficiency of the compressor and refrigerant. I am guessing at 0.123/0.263 = 47 %.

,

 

[westelectric]

i dont buy it or make it. i throw 3 bottled waters in the freezer the night before and 3 in the fridge, then put all in my cooler in the morning. everything stays nice and cold. not to mention all the polite customers who offer you cold ice water all the time while you sweat your #$&^%'s off.

 

[gar]

100809-25 EST

chris:

One more complete warm cool cycle.

Total of 0.77 KWH, and 3.03 hrs. Thus, KWH to cool water was 0.77 -0.173 * 3.03 = 0.77 -0.524 = 0.246 KWH. Close to the first preliminary estimate.

This freezer still does not have a lot of food in it. Lots more blackberries and other berries to go into freezer. The warm cool periods lengthened as would be expected.

Should not cost you very much to freeze your water.

.

 

[gar]

100809-2255 EST

One more reference point is that my two freezers are costing me about 10 KWH per day at about 85 to 90 deg F ambient.

.

 

[chris kennedy]

Thanks Gordon.

 

[petersonra]

I have been told that some McDonalds around here sell 10 pounds of ice for 99 cents. WalMart sells it in 20 pound bags for under $2.

 

[mivey]

I have been told that some McDonalds around here sell 10 pounds of ice for 99 cents.

They do. It's the $20 for the Coke to go with it that's the deal-killer. :grin:

 

[gar]

100810-2057 EST

chris:

Is your freezer a combination refrigerator and freezer or a plain freezer?

How many cubic is the freezer rated at?

Is this a new high efficiency energy star device?

My freezer is 18 cu-ft, 1972, has a current load of about 3.76 A at 123 V near the end of the cool cycle. Thus, not an Energy Star freezer.

Do you have a wattmeter?

For 10 # of ice you will need to freeze about 5 quarts of water per day.

.

 

[petersonra]

10 lbs of ice will require the removal of about 1500 BTUs of heat to change the water to ice at 32 degrees. if the water going in is at 50 degrees, lets call it an additional 200 BTUs to cool it to 32 degrees.

So you are looking at removing about 1700 BTUs of heat, which is about 1/2 kw-hr.

IIRC, you can remove almost 10 kw-hrs worth of heat for 1 kw-hr worth of electricity in a freezer so you are looking at something like 1/20 of a kw-hr of electricity to freeze ten pounds of ice.

 

[LarryFine]

if the water going in is at 50 degrees . . .

In this heat? It feels like 80+ once the inside cooled water has run out, which would be no cooler than the house.

 

[rattus]

Idea!

Idea!

You could get one of those canvas canteens that they used before ice was invented. A little water would seep through the canvas and evaporate which cooled the water inside. Hung them on the outside of automobiles. Cheap!